Half to john c



(No Modl.) n

- Gr. T. HETZEL.

LOCK. l v l .Na 532,877.. Patented Jan. 22, 1895.

NITED STATES PATENT OEEICE.

GEORGE T. HETZEL, OF ALLEGHEN Y, PENNSYLVANIA, ASSIGNOR OF ONE- HALF TO JOHN O. HE'TZEL'AND CHARLES H. HETZEL, OF SAME PLACE.

LOCK.

SPECIFICATION forming part of Letters Patent N o. 532,877, dated January 22, 1895. Applioationvled February 6, 1894. Serial No. 499.270.` (No model.)

To all whom it may concern:

Be it known that I, GEORGE T. HETZEL, a resident of Allegheny, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Locks; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to locks, and more particularly to that class of locks commonly known as tumbler locks, in that the tumbler must be raised by the key before the bolt can be moved. i.

The object of my invention is to provide a lock which is simple in construction and which has few parts, so that it is not liable to get out of order, while, at the same time, the locking mechanism is so protected as to prevent the picking of the lock.

To enable others skilled in the art to make and use my invention, I will describe the same morefully, referring to the accompanying drawings, in which- Figure l is an inside face View of my improved lock. Fig. 2 is an outside face view. Fig. 3 is a View of the interior of the lock showing the position of the locking mech-A anism when said lock is unlocked. Fig. 4. is a view showing the position o f the lookin g mechanism when the lock is locked fromv the inside. Fig. 5 is a like view when the lock is locked from the outside. Fig. 6 is a view of the tumbler removed. Fig. 7 is aview of the bolt removed; and Fig. 8 is a'view of the dog.

Like letters of reference indicate like parts in each of the figures of the drawings.

The box or shell a of my improved lock may be of the ordinary form, having the side plates o. a2, and the customary opening in the front face thereof for the passage of the bolt. able, being held in position by the screw a3. The inner plate a is provided with the keyopening b, and the outer plate 0.2 is provided with the key-opening b. The inner face of the outer plate a2 is provided with the recess a4 to receive the inner end of the key and act as a bearing therefor, and the inner plate a' is also provided with a like recess for the same purpose. These-key openings b b are One of said side plates ais remov-y non-coincident, for the purposes hereinafter more fully setforth.

Within the box or shell ais the tumbler c, said tumbler being pivoted to one of the Side plates, as at c', by means of the pin c2. The tumbler c has formed on the upper portion thereof the lug d, and the lug d at the lower portion thereof. The said tumbler c is further provided with the opening c, said opening being slightly beveled around the upper portion thereof, as at e', to allow for the clearance of the key in the raising of said tumbler and the moving of the bolt ,when the key is turned Within the key-opening b. The lower portion of said tumbler is also slightly beveled, as at e2, for the same purpose when the key is turned Within the key-opening b. The boltfis held within suitable guides g in such position that the lug f at the upper end of said bolt is normally held in engagement with the lug CZ on the upper portion of the tumbler c. The said bolt f is provided with theopening h, the periphery of said opening being of such shape and size as to allow for the turning of the key of any desired shape therein, and having the keygroove h to receive the end of the keyby which said bolt is moved. By having the tumbler c with the opening e and the bolt f with the opening h the key-opening b is inclosed on the inside by a wall which prevents the picking of the key-opening?) fromthe outside when the lock is locked from the inside, as will more fully appear. The lower end of said bolt f is provided with the key-groove t', which is engaged by the inner end of the key inserted in the inside key-opening b when said key is turned to move the bolt. A spring j secured within the box or shell a at j is adapted, by means of its free end, to hold the tumbler c in such position that the lug d of said tumbler will be normally vengaged by the lug j of the bolt f. A stop k is formed on the bolt f adapted to regulate the distance to which said bolt can be withdrawn.

Pivoted below the tumbler c is the dog Z, said dog being adapted to engage the lug d on the lower end of said tumbler c, and so prevent the raising of said tumbler, as more fully hereinafter set forth. The dog lis pro- IOO vents the said dog from moving too freely.`

A stop o on the plate a2 regulates the movement of said dog in that direction.

When it is desired to lock my improved lock from the inside the key is inserted in the key-opening b and turned, whereupon the said key turning in contact with the beveled portion e2 said tumbler will `be raised to release the lug d from engagement with the lug f of the bolt, and upon the .farther turning of the key, the said key entering the key-` groove i, will move the bolt to the position shown in Fig. 4. Upon the farther turning of the key said key will come in contact with` the projection Z2 on the dog Z and throw said dog into engagement with the lug d on the lower corner of said tumbler c, while thespring j will hold the said tumbler down in its nor-1 With the lock in the position shown in Fig. 4, to unlock the same from the inside it is only necessary to reverse the movement of the key, whereupon said key will lcome in contact with the projection Z of the dog Zand j act to throw said dog Z out of engagement with the lug d ofsaid tumbler, and upon the far-1 ther turning of said key the said tumbler will If, hOW- 1l ever, with the parts in the position shown in. Fig. et, the key is inserted in the key-opening; b in the outside plate a2 and said key turned v to raise the tumbler c, the dog Z being in en mal position.

be raised and the bolt withdrawn.

gagement with the lug d of said tumbler will prevent the raising of said tumbler tol free the lug CZ from engagement with the lug f so that with the parts in the aforesaid position it is impossible to unlock the door from the On the contrary, if the key is ini outside. serted `in the key-opening b of the outer plate a2 and the parts brought into the position shown in Fig. 5, the lock cannot be unlocked by inserting a key in the key-opening b in the inner plate a; for if the key be inserted in said key-opening b in the inner plate a' the projection Z2 will prevent the turning of the key in one direction and the bolt itself the turning in the opposite direction. The dog Z will `prevent the raising of the tumbler c and the consequent withdrawal of the bolt.

From the above construction it is apparent that if the lock is locked from the inside any attempt to pick the lock from the outside would be futile from the fact that the key openings are non-coincident, and from the fact that there is no open way for getting at the inside key-hole from the outside key-hole, as the lower portions of the tumbler and bolt completely shut off the space about the outer key-hole and form a wall between said keyholes.

What I claim `as my invention, and desire `tosecure by Letters Patent, is-

l. In a lock, the combinationof the box or shell a, having key-openings 19,19', the bolt f, the tumbler c, the spring j, and the dog Z, substantially as set forth.

2. In a lock, the combination with a box or shell having non-coincident key-openings, of a bolthaving an opening therein coincident with one of said key-openings, a tumbler havingan opening therein coincident with said opening in said bolt,and mechanism adapted to retain said tumbler in a fixed position as to one of said key-openings when said bolt is shot, substantially as and 'for the purposes set forth.

3. In a lock, the combinationwith a box or shell having key-openings on opposite sides thereof, the one above the other, of a bolt GEORGE T. HETZEL.

Witnesses:

Roer. D. To'rTEN, J. N. COOKE. 

